Question: What do the following two equations represent? $x+4y = 1$ $-x-4y = -1$
Explanation: Putting the first equation in $y = mx + b$ form gives: $x+4y = 1$ $4y = -x+1$ $y = -\dfrac{1}{4}x + \dfrac{1}{4}$ Putting the second equation in $y = mx + b$ form gives: $-x-4y = -1$ $-4y = x-1$ $y = -\dfrac{1}{4}x + \dfrac{1}{4}$ The above equations turn into the same equation, so they represent equal lines.